Interior wall cap for use with an exterior wall of a building structure

ABSTRACT

A wall cap comprising an end cap and insulating sound-dampening material can be installed with a building structure having an interior wall to decrease the transmission of sound and vibration from the building structure to the interior wall.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/461,383, filed Jan. 18, 2011, and U.S. ProvisionalPatent Application No. 61/510,634, filed Jul. 22, 2011, both of whichare incorporated herein by reference in their entirety.

BACKGROUND

Buildings having an exterior façade primarily composed of glasstypically comprise a non-loading bearing curtain wall which supports theglass. The curtain wall typically comprises an aluminum frame forsupporting the glass comprising a series of mullions for anchoring theframe to the building structure and may also provide a place to abutvertical and/or horizontal building partitions (e.g. walls,floors/ceilings). The mullions provide a space between the buildingpartitions and the glass which may result in undesirable soundtransmission between partitioned spaces within the building. The mullionmaterial may also contribute to the transmission of undesirable sound.

Conventional methods for minimizing sound transmission include addingmass to the mullion or adding sound absorbing materials to the mullion,such as filling the mullion with insulation. Another method involvesattaching a vibration isolation cover to the mullion face. In anotherexample, a partition wall is cantilevered out to meet the glass and thepartition wall is sealed with the glass using caulk.

These methods for minimizing sound transmission often requiremodifications for each building structure and typically do not providethe desired magnitude decrease in sound transmission. Methods such ascantilevering the partition wall out to meet the glass do not allow fordifferential movement between the building and the curtain wall system,which can result in tearing of the sealing caulk.

BRIEF SUMMARY

According to one embodiment of the invention, a wall cap for an interiorwall of a building structure, the building structure comprising at leastone exterior wall and at least one interior wall, a gap formed betweenthe at least one interior wall and the at least one exterior wall,comprises at least one elongated member having a first end configuredfor attachment to the at least one interior wall, and an underside forreceiving at least one sound-damping material, the underside of theelongated member defining a sound-receiving chamber with at least aportion of the interior wall. When the at least one elongated member ismounted in cantilever fashion to a portion of the interior wall andsubstantially fills the gap between the interior wall and thecorresponding exterior wall, at least one of sound and vibrationemanating from the building structure is dampened by the wall cap beforebeing transmitted to the interior wall structure.

According to another embodiment, the wall cap further comprises a legextending from the underside of the elongated member at a second endopposite the first end, the leg defining a portion of thesound-receiving chamber. At least one sealing member disposed between anexterior surface of the leg on the wall cap and an interior surface ofthe exterior wall structure.

According to another embodiment, at least one mullion is disposed in thegap at spaced intervals along the exterior wall, and at least one of theat least one interior wall is in register with the at least one mullion.The interior wall can abut the at least one mullion, and the wall capcan extend substantially across the gap to the exterior wall in front ofthe at least one mullion, in register with the at least one interiorwall. At least a portion of the exterior wall can be transparent or madeof glass.

According to yet another embodiment, the elongated member has an outersurface generally aligned with an interior wall surface of thecorresponding interior wall. The elongated member can be constructed ofat least one of aluminum, steel, and an aluminum alloy.

According to another embodiment, the sound-damping material can beconstructed of at least one of a multi-layer acoustical compositebarrier, a coated willtec open-cell foam layer, a mass loaded vinyllayer, a willtec decoupler layer, batting insulation, blanketinsulation, acoustic foam, mineral board, mass loaded vinyl, dampingcompounds, and combinations thereof.

According to another embodiment, the wall cap as a sound-transmissionrating of at least 50. The wall cap can have an outdoor-indoortransmission class rating of at least 40.

According to another embodiment, an additional wall cap can be mountedto an opposite side of the interior wall in opposed relationship to theother wall cap.

According to another embodiment, the wall cap can be fastened to theinterior wall by at least one of a snap-fit coupling, a threadedfastener, adhesive, and welding. A cover can be configured to concealthe attachment between the wall cap and the interior wall.

According to another embodiment, the first end configured for attachmentto the interior wall comprises an axially-extending leg in alignmentwith the elongated member.

According to yet another embodiment, the first end configured forattachment to the interior wall comprises an axially-extending legoffset from the elongated member by a depending member.

According to another embodiment, a building structure comprises at leastone exterior wall and at least one interior wall, the at least oneinterior wall forming a gap with respect to an interior surface of theexterior wall, the at least one interior wall comprising at least onewall cap. The wall cap can have at least one elongated member having afirst end configured for attachment to the at least one interior walland an underside for receiving at least one sound-damping material, theunderside of the elongated member defining a sound-receiving chamberwith at least a portion of the interior wall. When the at least oneelongated member is mounted in cantilever fashion to a portion of theinterior wall and substantially fills the gap between the interior walland the corresponding exterior wall, at least one of sound and vibrationemanating from the building structure is dampened by the wall cap beforebeing transmitted to the interior wall structure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of a portion of a building having a curtainwall, as is known in the prior art.

FIG. 2 is a partial cross-sectional view of the building structure andcurtain wall of the prior art of FIG. 1 taken along the line 2-2.

FIG. 3 is a perspective view of a portion of the building of FIG. 1having a plurality of wall caps according to an embodiment of theinvention

FIG. 4 is a perspective view of the wall cap of FIG. 3 according to anembodiment of the invention.

FIG. 5 is a partial cross-sectional view of the wall cap of FIG. 2 takenalong the line 5-5 according to an embodiment of the invention.

FIG. 6 is a partial cross-sectional view of the wall cap of FIG. 5installed with a plurality of gaskets according to an embodiment of theinvention.

FIG. 7 is a is a partial cross-sectional view of the wall cap of FIG. 6installed on one side of the mullion of FIG. 2 according to anembodiment of the invention.

FIG. 8 is a partial cross-sectional view of a sound chamber test set-up.

FIG. 9 is a partial cross-sectional view of a wall cap in use with thesound chamber test set-up of FIG. 8.

FIG. 10 is a partial cross-sectional view of a building structure andwall cap according to an embodiment of the invention.

FIG. 11 is a partial cross-sectional view of a building structure andwall cap according to an embodiment of the invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a portion of a building structure 12 having aplurality of partitions 20 forming multiple areas or rooms 13 within thebuilding structure 12 and having a curtain wall 10, as is known in theart. The curtain wall 10 shares many features of a traditional curtainwall, which will not be described in detail except as necessary for acomplete understanding of the invention. As illustrated in FIG. 1, thecurtain wall 10 forms an exterior or outer wall of the buildingstructure 12. Curtain walls are typically non-structural walls that donot carry any load weight of the building, other than its own loadweight, but rather form a façade of the building structure. A curtainwall is typically used to provide a building with an exterior wallformed of glass, for example. While the curtain wall 10 is illustratedas an exterior façade of the building structure 12, ribbon windows andwindow walls might also be used for the façade of the buildingstructure. A window wall can also be used as an interior partition wallfor an area inside the building structure 12.

FIG. 2 is a cross-sectional view of a portion of the curtain wall 10anchored to the building structure 12 that can be used with theembodiments of the invention described herein. The curtain wall 10comprises mullion 14 which supports in-fills 16 that can be made ofglass, metal or thin stone, for example. The mullion 14 can be made fromany suitable metal or metal alloy material, but is typically made ofAluminum. The mullion 14 can abut a vertical partition, such aspartition 20, and/or horizontal partition, such as a floor, of thebuilding structure 12 as is known in the art. The exact manner by whichthe mullion 14 is anchored to the building structure 12 is not germaneto the invention. A plurality of mullions 14 can be used to anchor aplurality of in-fills 16 to the building structure 12, as is known inthe art.

The partition 20 can be a vertical partition (as shown in FIG. 1), suchas an interior wall or an exterior wall, or a horizontal partition (notshown), such as a floor or ceiling, for example. The partition 20 caninclude a first side 22, a second side 24 and an end 26 hung on aframing system comprising at least one stud 28. The stud 28 can be madeof wood, metal or metal alloy, and is typically made of steel. Thepartition 20 can be made of drywall, gypsum wallboard, sheet rock orplasterboard, for example, and can have any suitable length depending onthe architecture of the building. The partition 20 can be filled withany suitable type of insulation 30, such as fiberglass insulation, as isknown in the art. The partition 20 can optionally also include resilientchannel strips 31, that are commonly installed with drywall to offsetthe drywall from the framing system.

Optional first and second trim pieces 32, 34 can be mounted on thepartition 20 adjacent the mullion 14 for aesthetic reasons and can bemade of the same material and have the same finish as the mullion 14. Inone example, the first and second trim pieces 32, 34 can be made oflight gauge aluminum.

Referring now to FIGS. 3 and 4, a wall cap in the form of a mullion cap50 comprising an end cap 52 and a sound insulating material 54 isinstalled with the building structure 12 of FIGS. 1 and 2. The end cap50 includes a first leg 56 and a second leg 58 extending from a firstend of the first leg 56. The first leg 56 can include one or moreapertures 60 for securing the mullion cap 50 to a structure. The end cap52 can be made of any suitable metal, polymeric, composite, metal alloyor wood material and have any suitable color or finish to provide thedesired aesthetic appearance. For example, the end cap 52 can be analuminum extrusion that is anodized or painted to match the finish ofthe curtain wall 10 and mullion 14. The first leg 56, the second leg 58and the adjacent portion of the partition 20 can define asound-receiving chamber which is provided with sound insulating material54 to dampen sound and vibration emanating from the building structure12 before being transmitted to the partition 20.

The mullion cap 50 can have any suitable length depending on theparameters of the structure in which the mullion cap 50 is beinginstalled. For example, the length of the mullion cap 50 can be based onthe height of the partition 20. The length of the first leg 56 andsecond leg 58 can vary depending on the distance between the partition20 and the curtain wall 10 and the width of the partition 20, forexample. It is also within the scope of the invention for the mullioncap 50 to not include the second leg 58.

The sound insulating material 54 can be any suitable material or layersof material for absorbing and deadening sound to provide a desired SoundTransmission Class (STC) rating. The STC is a single-number rating of amaterial's or an assembly's ability to resist airborne sound transfer atfrequencies of 125-4000 Hz. In general, a higher STC rating blocks morenoise from transmitting through a partition.

One example of a sound insulating material 54 is a multi-layeracoustical composite barrier, such as Prospec® Composite available fromPinta Acoustic Inc., which comprises a Hypalon® coated willtec open-cellfoam layer having a convoluted surface bonded to a mass loaded vinyllayer with a willtec decoupler layer. Additional non-limiting examplesinclude batt or blanket insulation, acoustic foam, mineral board, massloaded vinyl, damping compounds and combinations of different materials.

The sound insulating material 54 can be mounted to the end cap 52 usingany suitable mechanical or non-mechanical fasteners, non-limitingexamples of which include screws, clips, snaps, clamps, adhesive andwelds.

The mullion cap 50 can also include an optional trim piece 64 which canbe separate from the end cap 52 (FIG. 4) or integrally formed with theend cap 52 (not shown). When the trim piece 64 is not integrally formedwith the end cap 52, the trim piece 64 can be secured to the mullion cap50 and/or partition 20 any suitable mechanical or non-mechanicalfasteners, such as screws or an adhesive, for example, or the trim piece64 can be configured as a snap-on piece.

Referring now to FIG. 5, the first leg 56 of the end cap 52 can besecured to the partition 20 by fasteners 62 inserted through theapertures 60. The fasteners 62 can be any suitable type of mechanicalfastener, such as a bolt or screw, for example. The fastener 62 canextend through the partition wall 20 and optionally into the stud 28such that the mullion cap 50 can be secured to both the partition 20 andany underlying support structure of the partition 20. The optional trimpiece 64 can be secured over the fasteners 62 in the first leg 56 aspart of the mullion cap 50. The trim cap 64 can have the same colorand/or finish as the end cap 52.

While the mullion cap 50 is illustrated as being secured to thepartition 20 using the fasteners 62, it is within the scope of theinvention for the mullion cap 50 to be secured to the partition 20 usingany suitable mechanical or non-mechanical fastener, non-limitingexamples of which include screws, nails, adhesives, and/or double-sidedtape.

The mullion cap 50 at least partially spans the distance from thepartition 20 to the in-fill 16 and extends into a gap defined by thein-fill 16, the mullion 14 and the partition end 26. The mullion cap 50and sound insulating material 54 can extend adjacent to, but spaced fromthe mullion 14. In one example, the distance between the soundinsulating material 54 of the mullion cap 50 and the mullion 14 isapproximately ⅛ of an inch, although this distance can vary depending onthe building structure and in some instances can range from 1/16 of aninch to 6½ inches. It is also within the scope of the invention for anouter surface of the sound insulating material 54 to be adjacent to andin contact with the mullion 14 along at least a portion of the mullion14. It is also within the scope of the invention that the distancebetween the sound insulating material 54 of the installed mullion cap 50and the mullion 14 is small enough such that movement and/or settling ofthe curtain wall 10 and/or building structure 12 results in contactbetween the mullion 14 and the sound insulating material 54 that may ormay not be temporary.

As illustrated in FIG. 5, the mullion cap 50 does not span the entiredistance from the partition 20 to the in-fill 16, but is spaced from thein-fill 16 to allow for differential movement between the curtain wall10 and the building structure 12. For example, the second leg 58 of theend cap 52 can be spaced approximately 1/16 to ¼ of an inch from thein-fill 16. It is also within the scope of the invention that thedistance between the sound second leg 58 of the end cap 52 and thein-fill 16 is small enough such that movement and/or settling of thecurtain wall 10 and/or building structure 12 results in contact betweenthe second leg 58 and the in-fill 16 that may or may not be temporary.The mullion cap 50 is anchored to the partition 20 such that the mullioncap cantilevers off of the partition 20. Even though movement and/orsettling of the curtain wall 10 and/or building structure 12 may resultin contact of the mullion cap 50 with the in-fill 16 over time, themullion cap 50 is not supported by or anchored to the in-fill 16.

Referring now to FIG. 6, it is also within the scope of the inventionfor one or more gaskets or compressible seals 68, such as a neoprenegasket, to be provided between the second leg 58 of the end cap 52 andthe in-fill 16.

While FIGS. 5 and 6 illustrate the use of the mullion cap 50 on bothsides of the partition 20, it is also within the scope of the inventionfor the mullion cap 50 to only be used on a single side of the partition20, as illustrated in FIG. 7, with gaskets (FIG. 7) or without gaskets68 (not shown).

Optionally, acoustical sealant, such as OSI Acoustic/Sound Sealant, canbe used at various joints within the system such as between the end cap52 and the partition 20, between the mullion 14 and the partition 20 andbetween the mullion 14 and the in-fill 16.

While the mullion cap 50 is illustrated as comprising an end cap 52having a first leg 56 and a second leg 58, it is also within the scopeof the invention for the end cap 52 to only comprise the first leg 56.For example, when used without the gasket 68, the second leg 58 may notbe needed. When the gasket 68 is used with the mullion cap 50, such asis shown in FIG. 6, the second leg 58 can provide a surface to which thegasket 68 can be secured.

While the mullion cap 50 is described with respect to the curtain wall10, the mullion cap 50 can be used with any curtain wall or comparablebuilding structure, such as a ribbon wall, strip windows, storefront, orother glass support systems, for example.

Acoustical testing for a partition/curtain wall/mullion interfaceassembly with and without a mullion cap was determined in accordancewith the following American Society for Testing and Materials (ASTM)standards: ASTM E 90-09, Standard Test Method for Laboratory Measurementof Airborne Sound Transmission Loss of Building Partitions; ASTM E413-10, Classification for Rating Sound Insulation; ASTM E 1332-10a,Standard Classification for Rating Outdoor-Indoor Sound Attenuation;ASTM E 2235-04, Standard Test Method for Determination of Decay Ratesfor Use in Sound Insulation Test Methods.

Test Set-Up Descriptions

The test equipment used to conduct the tests meet the requirements ofASTM E 90. The microphones were calibrated before conducting soundtransmission loss tests.

Sound transmission loss tests were initially performed on a filler wallthat was designed to test 48 inch by 72 inch and 72 inch by 48 inchspecimens. The filler wall is described in more detail below in thedescription of Sample A. The filler wall achieved an STC rating of 69. A48 inch by 72 inch plug was removed from the filler wall assembly andthe sample was placed on an isolation pad in the test opening formed bythe removal of the plug. Duct seal was used to seal the perimeter of thesample to the test opening on both sides. The interior side of thesample, when installed, was approximately ¼ inch from being flush withthe receiving room side of the filler wall.

Sample A:

The test set-up for sample A is illustrated schematically in FIG. 8.FIG. 8 illustrates a partition/curtain wall/mullion interface assemblytest set-up comprising a portion of a test curtain wall 210 and a testpartition 220 similar to the curtain wall 10 and partition 20 of FIGS. 1and 2 described above, except that the test curtain wall 210 comprises atest mullion 214 coupled with a sound chamber wall 280 for determiningthe STC rating of the system instead of in-fills of glass or metal.Therefore, elements of the test curtain wall 210 and test partition 220similar to those of the curtain wall 10 and partition 20 are labeledwith the prefix 200.

The test partition 220 (filler wall) comprises a portion of a demisingwall or interior wall consisting of a single 6 inch, 20 gauge steel studwall with studs 228 spaced on 24 inch centers. One layer of ⅝ inchgypsum board 224 was fastened to the vertical studs 228 on a receiveside 282. On a source side 284, 25 gauge resilient channels 231 werehung horizontally on the studs 228 (24 inch centers). One layer of ⅝inch gypsum board 222 was fastened to the resilient channels 286 on 24inch centers. The cavity of the test partition 220 was insulated with 5inch thick, 4 pounds per ft³ Thermafiber mineral wool insulation 230.

A section of test mullion 214 was installed in a 5 5/16 inch wide by 72inch high gap 300 between the test partition 220 and a sound chamberwall test opening 302. The test mullion 214 was a box extrusion typemade of aluminum, 5 5/16 inch by 72 inches by 2½ inch, having anextrusion wall thickness of 0.092 inches and weighing 1.74 pounds perlineal foot. The test mullion 214 was sealed to the test opening 302 onboth sides using an acoustic sealant. The test mullion 214 was notsealed to the test partition 220. Light gauge aluminum trim 232, 234 wasused to cap the area between the face of the test partition 220 and thetest mullion 214 on both sides. The light gauge trim 232, 234 was an “L”channel type made of Aluminum, 2 15/16 inch by 72 inches by 1⅛ inch,having a material thickness of 0.053 inch and weighing 0.22 pounds perlineal foot.

Sample B:

The test set-up for sample B was similar to sample A except that thealuminum trim 232, 234 was removed, and is illustrated schematically inFIG. 9. An exemplary mullion cap 450 was installed on both sides of thetest partition 220, extending across the gap 300 adjacent the testmullion 214. The exemplary mullion cap 450 is similar to the mullion cap50 of FIGS. 3-7, therefore elements of the exemplary mullion cap 450similar to the mullion cap 50 of FIGS. 3-7 are labeled with the prefix400. The mullion caps 450 were fastened to the test partition 220 withdrywall screws 462 and sealed using acoustical sealant. The mullion caps450 were sealed to the vertical section of the test opening 302 with ⅛inch thick ( 1/16 inch compressed) neoprene gaskets 468 and sealed tothe test opening 302 at the top and bottom with acoustical sealant. Themullion cap 450 comprises an end cap 452 made of 0.130 inch thickaluminum and insulating material 454 comprising a 0.340 inch thickclosed cell foam layer, a 0.085 inch thick mass loaded vinyl layer and a0.670 inch thick closed cell foam layer. The mullion cap 450 had aweight of 1.84 pounds per lineal foot and measured 6 13/16 inch by 72inches by 1½ inch. There was a ⅞ inch (nominal) air gap between aninterior face of the closed cell foam and the test mullion 214.

Sample C:

The test set-up for sample C was similar to sample B except that themullion cap 450 on the source side 284 of the test partition 220 wasremoved.

Sample D:

The test set-up for sample D was similar to sample B except that theneoprene gaskets 468 between the mullion caps 450 and the test opening302 were removed, providing a 1/16 inch gap between the test opening 302and the mullion caps 450.

Table 1 below lists the STC and OITC results for Samples A-D. The STCrating was calculated in accordance with ASTM E 413. The OITC(Outdoor-Indoor Transmission Class) rating was calculated in accordancewith ASTM E 1332.

TABLE 1 STC and OITC Ratings for Mullion with and without Mullion CapsSample Description STC OITC A Without mullion caps 28 28 B Mullion capson both sides 54 41 with gasket C Mullion cap on one side with 51 41gasket D Mullion cap on both sides 54 40 without gasket

As can be seen from the test results in Table 1, the use of the mullioncap 450 increases the STC rating of the test assembly from 28 to 54,meaning sound transmission is decreased when a mullion cap is installed.Even the use of a single mullion cap on one side of the mullion (sampleC) decreases the sound transmission through the test partition/curtainwall/mullion interface assembly.

Referring back to FIG. 1, sound waves, illustrated schematically aswaves 70, are transmitted between rooms 13 through the mullions 14 andin-fills 16 of the curtain wall 10. As illustrated by the test results,a typical demising wall, such as the filler wall used in the testset-up, can be provided with sufficient structure and insulation to havean STC rating of 69. An STC rating greater than 60 is generallyconsidered to correspond to enough sound proofing to render most soundsfrom an adjacent room inaudible. However, as illustrated by test sampleA, a curtain wall system comprising a mullion can have an STC rating aslow as 28. This is significantly less than the STC rating of theadjacent wall and generally low enough such that loud speech on theopposite side of the wall can be heard and possibly understood.Therefore, most of the sound transmitted between rooms 13 in thebuilding structure 12 is through the mullions 14, not the partitions 20.In this manner, building structures utilizing curtain wall systems oftenhave much lower overall STC ratings than similar building structuresthat do not utilize curtain wall systems. The transmission of soundbetween rooms in a building can be annoying and distracting to occupantsand can also raise privacy issues.

As illustrated in FIG. 3 and supported by the test data above, the useof a mullion cap as described herein in a building structure having acurtain wall system can dramatically decrease the transmission of soundwaves, illustrated as waves 72. The use of the mullion cap 450 in thetest set-ups B-D significantly increased the STC rating of the systemfrom 28 to greater than 50. STC ratings above 50 are generallyconsidered to correspond to loud sounds such as musical instruments or astereo as being faintly audible, but not enough to bother the majorityof the population. The use of the mullion cap described herein allowsfor the use of a curtain wall system without the sacrifice in soundattenuation normally ascribed to curtain wall systems.

FIG. 10 illustrates a wall cap 550 which is similar to the wall cap 50except for the profile of the wall cap 550. The wall cap 550 can be usedwith a building structure 512 which is similar to the building structure12 except for the partition 520. Therefore, elements of the wall cap 550and building structure 512 similar to those of the wall cap 50 andbuilding structure 12 will be numbered with the prefix 500.

Still referring to FIG. 10, the building structure 512 includes apartition 520 which comprises an acoustic rated wall construction 600and first and second drywall sides 522 and 524 installed on an outsideface of the acoustic rated wall construction 600. The wall cap 550includes first leg 556 and a second leg 558 extending from the first endof the first leg 556. The second leg 558 is positioned adjacent thein-fills 516 when installed with the building structure 512. The wallcap 550 further includes a third leg 602 at a second end of the firstleg 556, opposite the second leg 558. A fourth leg 604 extends from anend of the third leg 602 opposite the end connected with the first leg556, and is generally parallel to, but offset from, the first leg 556.The offset profile allows for the wall cap 550 to be used when thepartition 520 is offset from the center of the mullion 514, the width ofthe partition 520 is not sufficient to accommodate the dimension of thesecond leg 558, or the width of the mullion 514 is too large toaccommodate the dimension of the second leg 558.

The wall caps 550 are secured to the acoustic rated wall construction600 through the fourth leg 604 using one or more fasteners 562 andcantilever out over the mullion 514. The first and second drywall sides522 and 524 are installed such that the drywall sides 522, 524 cover thefourth leg 604, with a distal end of the drywall sides 522, 524generally abutting the third leg 602 of the wall caps 550. Asillustrated in FIG. 10, the length of the third leg 602 is such that thefirst leg 556 of the wall caps 550 are not flush with the drywall sides522, 524. Alternatively, the length of the third leg 602 can beconfigured such that the first leg 556 is generally flush with thedrywall sides 522, 524.

FIG. 11 illustrates another embodiment of the invention in which thewall cap 50 is used with a building structure 712 and curtain wall 710.Therefore, elements of the building structure 712 and curtain wall 710similar to those of the building structure 12 and curtain wall 10 willbe labeled with the prefix 700.

The wall cap 50 can be secured to the building structure 712 in the samemanner as described above with respect to the building structure 12. Thewall cap 50 can be installed such that the wall cap 50 cantilevers offof the partition 720 and spans the gap between the end 726 of thepartition 720 and the infill 716. The wall cap 50 can be configured suchthat the second leg 58 is positioned adjacent to the infill 716.

As illustrated in FIG. 11, the wall cap 50 can be used to span thedistance between a partition and the adjacent infill even when nomullion is present. The wall cap 50 can be used with a curtain wall,which is secured to the outside edge of a building frame, interiorpartitions, and storefront and window wall structures that are formedwithin the perimeter of the building frame, with or without a mullion ina manner similar to that described above with respect to FIG. 11.

The wall cap described herein provides an aesthetically appealing anddurable system for decreasing sound transmission through buildingpartitions at the exterior perimeter or interior of a building having acurtain wall, window wall, ribbon window, or any wall system thatutilizes a hollow tube framing system. The wall caps can be provided ina variety of colors and finishes to provide a desired aestheticappearance. The wall caps can be assembled, packaged and shipped to thebuilding site for installation and can easily be trimmed to the desiredlength and to fit around horizontal mullions, stepped sills or otherobstructions on-site. The wall caps can be installed during buildingconstruction or retrofitted to existing structures and can be used withmost curtain wall systems. In addition, when installed, the wall capscan be spaced from the mullion, thus allowing for differential movementbetween the building structure and the curtain wall system.

Because the wall cap cantilevers off of an adjacent partition and is notmounted to the mullion or the in-fill, the wall cap can be configuredfor use in a variety of different situations in which a partitionterminates at a curtain wall, glass store front, window wall and/orinterior glass partition, with or without a mullion. The wall cap can beused to decrease sound transmission between adjacent partitioned spacesregardless of whether the wall cap encompasses a mullion. This may bethe case when a mullion system is not in use or when the partitionterminates at a location not adjacent to a mullion. This provides thebuilder with added flexibility in designing and constructing spaces.

The wall cap also acts as a trim piece that conceals and trims the endof the partition which the wall cap cantilevers off of. For example,when the wall cap is used with a drywall partition, such as that shownin FIG. 2, the trim pieces 32 and 34 are not necessary. In this mannerthe wall cap provides both a functional benefit in that the transmissionof sound through the mullion is decreased and an aesthetic benefit inthat additional trim pieces are not needed.

The 2009 International Building Code requires demising walls ofmulti-family dwellings to have an STC rating of 50. The 2010 Guidelinesfor Design and Construction of Health Care Facilities has designcriteria of a minimum STC rating of 45 between patient rooms and aminimum STC rating of 50 between intensive care rooms. As evidenced bythe test data of Table 1, traditional curtain wall assemblies are unableto satisfy these requirements. The wall cap described herein provides aneconomical and easy to install system that is able to satisfy the 2009International Building Code and the 2010 Guidelines for Design andConstruction of Health Care Facilities requirements that can beinstalled during construction or retrofitted to existing structures. Theinsulation material provided with the wall caps can be selected based onthe desired STC rating while taking budget concerns into consideration.

To the extent not already described, the different features andstructures of the various embodiments may be used in combination witheach other as desired. That one feature may not be illustrated in all ofthe embodiments is not meant to be construed that it cannot be, but isdone for brevity of description. Thus, the various features of thedifferent embodiments may be mixed and matched as desired to form newembodiments, whether or not the new embodiments are expressly disclosed.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation. Reasonable variationand modification are possible within the scope of the forgoingdisclosure and drawings without departing from the spirit of theinvention which is defined in the appended claims.

1. A wall cap for an interior wall of a building structure, the buildingstructure comprising at least one exterior wall and at least oneinterior wall, a gap formed between the at least one interior wall andthe at least one exterior wall, the wall cap comprising: at least oneelongated member having a first end configured for attachment to the atleast one interior wall, and an underside for receiving at least onesound-damping material, the underside of the elongated member defining asound-receiving chamber with at least a portion of the interior wall;wherein, when the at least one elongated member is mounted in cantileverfashion to a portion of the interior wall and substantially fills thegap between the interior wall and the corresponding exterior wall, atleast one of sound and vibration emanating from the building structureis dampened by the wall cap before being transmitted to the interiorwall structure.
 2. The wall cap of claim 1 and further comprising a legextending from the underside of the elongated member at a second endopposite the first end, the leg defining a portion of thesound-receiving chamber.
 3. The wall cap of claim 2 and furthercomprising at least one sealing member disposed between an exteriorsurface of the leg on the wall cap and an interior surface of theexterior wall structure.
 4. The wall cap of claim 1 and furthercomprising at least one mullion disposed in the gap at spaced intervalsalong the exterior wall, and at least one of the at least one interiorwall is in register with the at least one mullion.
 5. The wall cap ofclaim 4 wherein the interior wall abuts the at least one mullion, andthe wall cap extends substantially across the gap to the exterior wallin front of the at least one mullion, in register with the at least oneinterior wall.
 6. The wall cap of claim 5 wherein at least a portion ofthe exterior wall is transparent.
 7. The wall cap of claim 5 wherein atleast a portion of the exterior wall is made of glass.
 8. The wall capof claim 1 wherein the elongated member has an outer surface generallyaligned with an interior wall surface of the corresponding interiorwall.
 9. The wall cap of claim 1 wherein the elongated member isconstructed of at least one of aluminum, steel, and an aluminum alloy.10. The wall cap of claim 1 wherein the sound-damping material isconstructed of at least one of a multi-layer acoustical compositebarrier, a coated willtec open-cell foam layer, a mass loaded vinyllayer, a willtec decoupler layer, batting insulation, blanketinsulation, acoustic foam, mineral board, mass loaded vinyl, dampingcompounds, and combinations thereof.
 11. The wall cap of claim 1 whereinthe wall cap has a sound-transmission rating of at least
 50. 12. Thewall cap of claim 1 wherein the wall cap has an outdoor-indoortransmission class rating of at least
 40. 13. The wall cap of claim 1and further comprising an additional wall cap mounted to an oppositeside of the interior wall in opposed relationship to the other wall cap.14. The wall cap of claim 1 wherein the wall cap is fastened to theinterior wall by at least one of a snap-fit coupling, a threadedfastener, adhesive, and welding.
 15. The wall cap of claim 14 andfurther comprising a cover configured to conceal the attachment betweenthe wall cap and the interior wall.
 16. The wall cap of claim 1 whereinthe first end configured for attachment to the interior wall comprisesan axially-extending leg in alignment with the elongated member.
 17. Thewall cap of claim 1 wherein the first end configured for attachment tothe interior wall comprises an axially-extending leg offset from theelongated member by a depending member.
 18. A building structurecomprising at least one exterior wall and at least one interior wall,the at least one interior wall forming a gap with respect to an interiorsurface of the exterior wall, the at least one interior wall comprising:at least one wall cap having at least one elongated member having afirst end configured for attachment to the at least one interior walland an underside for receiving at least one sound-damping material, theunderside of the elongated member defining a sound-receiving chamberwith at least a portion of the interior wall; wherein, when the at leastone elongated member is mounted in cantilever fashion to a portion ofthe interior wall and substantially fills the gap between the interiorwall and the corresponding exterior wall, at least one of sound andvibration emanating from the building structure is dampened by the wallcap before being transmitted to the interior wall structure.
 19. Thebuilding structure of claim 18 wherein the at least one wall cap furthercomprises a leg extending from the underside of the elongated member ata second end opposite the first end, the leg defining a portion of thesound-receiving chamber.
 20. The building structure of claim 18 andfurther comprising at least one mullion disposed in the gap at spacedintervals along the exterior wall, and at least one of the at least oneinterior wall is in register with the at least one mullion.
 21. Thebuilding structure of claim 20 wherein the interior wall abuts the atleast one mullion, and the at least one wall cap extends substantiallyacross the gap to the exterior wall in front of the at least onemullion, in register with the at least one interior wall.
 22. Thebuilding structure of claim 18 wherein the sound-damping material isconstructed of at least one of a multi-layer acoustical compositebarrier, a coated willtec open-cell foam layer, a mass loaded vinyllayer, a willtec decoupler layer, batting insulation, blanketinsulation, acoustic foam, mineral board, mass loaded vinyl, dampingcompounds, and combinations thereof.
 23. The building structure of claim18 wherein the at least one wall cap has a sound-transmission rating ofat least
 50. 24. The building structure of claim 18 wherein the at leastone wall cap has an outdoor-indoor transmission class rating of at least40.
 25. The building structure of claim 18 and further comprising anadditional wall cap mounted to an opposite side of the interior wall inopposed relationship to the other wall cap.
 26. The building structureof claim 18 wherein the at least one wall cap is fastened to theinterior wall by at least one of a snap-fit coupling, a threadedfastener, adhesive, and welding.